1-(1,3-Benzodioxol-5-yl)ethanone

In the title compound, C9H8O3, the dihedral angle between the mean planes of the benzene and dioxole rings is 1.4 (8)°, with the dioxole group in a slightly distorted envelope configuration with the flap C atom displaced by 0.0645 Å from the plane through the other four atoms. In the crystal, weak intermolecular C—H⋯O hydrogen-bond interactions link the molecules into chains propagating in [011]. The crystal packing exhibits weak π–π interactions as evidenced by the relatively short distances [3.801 (9) Å] between the centroids of adjacent benzene rings.

In the title compound, C 9 H 8 O 3 , the dihedral angle between the mean planes of the benzene and dioxole rings is 1.4 (8) , with the dioxole group in a slightly distorted envelope configuration with the flap C atom displaced by 0.0645 Å from the plane through the other four atoms. In the crystal, weak intermolecular C-HÁ Á ÁO hydrogen-bond interactions link the molecules into chains propagating in [011]. The crystal packing exhibits weakinteractions as evidenced by the relatively short distances [3.801 (9) Å ] between the centroids of adjacent benzene rings.
QNMHA thanks the University of Mysore for use of their research facilities. RJB acknowledges the NSF MRI program (grant No. CHE-0619278) for funds to purchase an X-ray diffractometer.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: IM2174).
intermediate for pharmaceuticals, agrochemicals and other organic compounds, as a drug to induce sleep and as a solvent for plastics, resins, cellulose ethers, and esters. Acetophenone and its derivatives are ingredients of flavor and fragrance for soaps, detergents, cosmetics, and perfumes as well as in foods, beverages, and tobacco. Many synthetic or naturally occurring compounds containing the 1,3-dioxolyl group are very important because of their pharmacological properties (Ma et al. 1987a,b;Ohta & Kimoto 1976;Krause & Goeber 1972;Gabrielsen et al. 1992). The crystal structure of 1,3-benzodioxol-5-ylmethanol (Yathirajan et al., 2007) is reported. The title compound, (I), was used recently for the synthesis of (2E)- prop-2-en-1-one (Jasinski et al., 2008). In view of the importance of the title compound, C 9 H 8 O 3 , (I), we report the crystal structure.
The molecular structure consists of an ethanoyl group bonded to a benzene group which is fused to a 1,3-dioxol ring in a nearly planar fashion (Fig. 1). The dihedral angle between the mean planes of the benzene and dioxol ring is 1.4 (8)°, as the dioxol group maintains itself in a slightly distorted envelope configuration (Cremer & Pople, 1975) with puckering parameters Q(2) and Phi(2) of 0.1020 and 34.7750, respectively. For an ideal envelope, Phi(2) has a value of k x 36. Bond lengths and bond angles are all within expected ranges (Allen et al. 1987).

Experimental
The title compound (I) was obtained from Aldrich Chemical Company and was recrystallized from DMF by slow evaporation

Refinement
All H atoms were placed in calculated positions and wer refined using the riding model with C-H = 0.95-0.98 Å, and with U iso (H) = 1.17-1.50U eq (C).